Multiple temperature household refrigerator



P 1952 G. A. GRUBB ET'AL 2,608,835

MULTIPLE TEMPERATURE uoussuow REFRIGERATOR Filed Feb. 26, 1948 3 Sheets-Sheet 1 Warm/ma Sept. 2, 1952 Filed Feb. 26, 1948 w G. A. GRUBB- ETAL MULTIPLE TEMPERATURE HQUSEHOLD REFRIGERATOR 3 Sheets-Sheet 2 P 1952 G. A. GRUBB ETAL 2,608,835

MULTFLE TEMPERATURETHQUSEHOLD REFRIGERATOR Filed Feb. 26, 1948 3 Sheets-Sheet 5 Warm/m5) embodied in a horizontal partition or shelf which may be employed as a supporting surface for ice. trays and the like and also serves as a top wall of a compartment adapted to receive frozen food packages and other matter to be frozen.

As diagrammatically shown in Fig. l, the cooling elements Ma and Nb are in the form of looped coils which are disposed one above the other. The cooling elements [4a and [4b and parts immediately associated therewith are connected in the gas circuit in such manner that I inert gas weak in refrigerant flows from the upper end of absorber coil 2| through inner passage-23 of the gas heat exchanger 18, conduit 24 and inner-passage 31 of a second gasheat exchanger 38 into one end of cooling elementHa. After flowing through cooling element Md, inert gas passes'through a connection 39, outer passage 40 of gas heat exchanger 38 and conduit 4| into the upper end of cooling element [4b. The inert gas flows downwardly through cooling element Nb and passes therefrom through conduit l6 which, as previously explained, is connected to the outer passage ll of gas heat exchanger l8 and through which inert gas rich in refrigerant flows to the absorber vessel 20. I

Liquid refrigerant is supplied from condenser.

I5 through conduits 42 and 43 to cooling elements I40, and [47), respectively. Refrigerant vapor flows successively through condenser sections lSa, I51) and 150, some refrigerant vapor liquefying and condensing in the first condenser section I511. Refrigerant vapor not liquefied in condenser section [in passes into condenser section [5b. and.

further condensation of refrigerant'is effected therein. Liquid refrigerant passes from conden- 1 ser section 1512 through conduit 42 to cooling ele- Refrigerment [4a for flow through the latter. ant vapor not liquefied in condenser section l5b passes through conduit 44 to condenser section I50 in which condensation of refrigerant is ef fect ed. Liquid refrigerant passes from condenser section [5c through conduit 43 into the upper end of cooling element 14b. 1

In order to insure liquid refrigerant being supplied tocooling element i4b when air cooling of the condenser [E is employed and the temperature of the air is relatively low, under which conditions there is a tendency for substantially all of the refrigerant vaporto be condensed in condenser sections [5a and 511, a conduit 45 havin a liquid trapformed therein is provided to divert liquid refrigerant from condenser section [5a into condenser section 150.

As diagrammatically illustrated in Fig. 1, liquid flows in adownward path of flow-in cooling element I40. in counterflow to inert gas which enters. from the inner passage 3'! of gasheat exing operation of the refrigeration systemand are operable at substantially the same pressure, that 4 is, the total pressure in the cooling elements 14a and 14b is substantially the same.

Since the inert gas flows successively through the cooling elements 14a and Nb, the gas in the cooling element l4a contains alesser amount of refrigerant vapor than in thecooling element 14b. The partial vapor pressure of the refrigerant is I a gradient, so that the temperature of liquid refrigerant in the cooling elements is also a gradicut, the evaporating temperature of liquid being lower in the cooling element Ha which constitutes the freezing section of the cooling structure H, In order to reduce and lower the mean or average temperature of cooling element Ha, the conduit '42 through which liquid refrigerant is supplied to that cooling element is arranged in thermal exchange relation with a part of coolin element I41), as indicated at 46. Further, the conduit 42 is arranged in thermal exchange relation with the outer passage 40 of gas heat exchanger 38, as indicated at 41. In this manner relatively coolgas flowing through the higher temperature cooling element 14b is first utilized to abstract heat from liquid refrigerant in conduit 42, and subsequently cooler ga flowing through the gas heat exchanger passage 40 is utilizedto abstract additional heat from such liquid refrigerant, thereby effectively precooling liquid refrigerant supplied to low temperature cooling element Ma.

By providing the second gas heat exchanger 38,

inert gas weak in refrigerant and flowing to the low temperature cooling element Ma will be effectively precooled by cool gas passing from the low temperature cooling element to the higher temperature cooling element l4b. Such heat transfer from weak gas in gas heat exchanger passage 31 to cool gas in passage 40 decreases the 7 49 whose other leg is connected to the absorber vessel 20 at a region which is below the normal liquid level therein.

By providing conduit 45 to divert liquid-refrigerant from the first condenser section 15a into the condenser section [50, liquid refrigerant will be initially supplied to cooling element 141) when: operation of the refrigeration system is started by applying heat to heating flue 30. This is necessary in order to start circulation of gas in the gas circuit since the low temperature cooling element I4a is located at a level between the upper end of absorber coil 2| and the liquid level in the absorber vessel 20. The circulation areas inthe gas circuit is effected by force developed within the refrigeration system'and is due to the difference in specific weight of inert gas enriched in refrigerant vapor and passing downwardly through cooling element I 4b to the absorber vessel 28,?and'that of inert gas weak in refrigerant vapor and passing upwardly from absorber coil i 2| to the cooling structure [4. Since the column of gas rich in refrigerant vapor and passing from cooling element I4a toathe absorber vessel 20 is heavier than the gas. weak in refrigerant and passing upwardly fromabsorber coil 2| through the conduit 24, a force. is developed within the system for causing circulation of inert gas in their mannerdescribed. The force thus developed for circulating gas in the gas circuit is of sufficient magnitude to cause upward flow of gas partially enriched in refrigerant from cooling element Me to cooling element Mb.

In order to simplify Fig. 1, the cooling structure H has been shown apart from a household refrigerator cabinet. One manner inwhich the coolingelements lda and.l4b of an absorption refrigeration system like that just described may. be

arranged in a .thermally insulated interior. of a household refrigerator cabinetin accord with the :invention, for cooling separate compartments therein, isdiagrammatically illustrated in Figs.

2 and 3; In Figs. 2 and '3 thecoolingstructure 1 I4 is. disposed .in'a cabinet 50 having a space'EI defined .by1an inner liner or Shelli? which is arranged 'to'beasupported"within an outer metal shell Wand insulated therefrom-withanysuite able insulating material 55-.- The space 5| is provided with 'a front access opening which-is adapted to ;be closed by-.an:insulated door 56 hinged to thefront of the cabinet 58.

lniorder to position the coolingelements Ma,

andMb in the space 5!, the rear wallB'l of the cabinet 50 is formed with upper and lower openings,,58 and'58a defined by rectangular frames 59 ;and 59a, respectively, which are formed, of a material like wood, for example. Covers or closure -members 60 and 60a containing insulating material BI and 6 la are provided for the openings 58 and 58a. The closure members 60 and tea are arranged to bear against insulating gaskets 62, 63 and 62a, 63a,-respectively,'and removably secured to the rear wall 51in any suitable manner (not shown). 7

The cabinet 58 is provided with a vertically extending apparatus compartment 84 at the rear thereof in which parts of the refrigeration system are housed, in a manner well known in the art. While only parts of the refrigeration system of Fig. 1 are seen in the compartment 64; it

is to be understood that the system illustrated in Fig. 2 is generally like that of Fig. 1 with similar parts designated by thesame reference numerals.

In Figs. 2 and 3 it will be seen that cooling ele-.

ment Mb associated with the upper closure member 60 is disposed within a metal shell or housing Fig: 3,the looped coil may be in thermal contact with the top and side wall of the housing 65 and is.out of direct" physical contact with air. in the space 5|.

The. cooling element Ma, comprises a looped coi1'j .h'aving straight portions and connecting bends disposed essentially in a single horizontal plane. This looped coil is disposed within and in good thermal contact with the top and bottom walls of "a housing or'shell 66 which extends from one' side wall to the opposite side wall of the inner shell 53, and from the rear wall thereof to a region closely adjacent to the rear face of the door- 56 when the latter is in its closed position. The housing 66 essentially serves as a horizontal partition to subdivide the space 5! into a bottom compartment 61 and a'higher located: compartment 6 8. l

rangement is provided for maintaining .frozenr food packages and other matterto be frozen at. alow'temperature in the bottomcompartm'entw which constitutes the freezing section of the re'---:v frigerator. This is so because air flowing in con.+.== tact with the bottom wall of the housing,.66-is: cooled and flows downwardly to displace lessgl cool air, thereby promoting natural circulation; of air whereby a substantially uniform tempera-i r: ture in all regions of the bottom compartment;- 61 will be maintained and a steepverticaltemperature gradient is avoided.

In thepreferred embodiment of the invention:.--- shown and being described, the gas circuit of the; refrigeration system lends itself to an arrange ment which makes it possible to provide a-freezsing section or deep freeze compartment at the: bottom of the cabinet spaceil. Accordingly,,the,-.: low temperature cooling element Ma is posie-e tionedat as low a level as possible with respect.

to the absorber vessel 20, as will be evident whenrr,

reference is made to Figs. 1 and 2.

If desired, the freezing compartment 61 at'the front access opening thereof may be provided; with a closure member (not shown). whichgis hinged to the front of the housing Siandspring biased inany suitable manner to its closed posttion. Such a closure member effectively prevents air from the higher located compartment 68 em; tering the freezing compartment 61,- whereby,

food products stored in the latter may be main-.-

tained at a desired low temperature. In .placeoffl such a closure member, the bottom wall ofthe housing 66 may have spaced. apart guide mem s here 69 fixed thereto adapted to slidably receive. and support the flanges 10 to open top vessels ,1 1'. preferably formed of sheet metal, as :shown. inf Figs. 2 and 3. Food products to be stored inth freezing compartment can be placed .in the Ivessels H, and, since the bottom wallof thehousing serves as a cover for the open topvessels, a. hinged closure member. of the kind just described; is not necessary for the freezing compartment. 61.1 While the vessels. may be. imperforatei, openings .may be provided in the side walls'.there.-.; of when circulation of air through the ,vesse'lslisf desired, as indicated by dotted lines .12 in Fig. 2. The top surface of the housing 65 is employed as. a supporting surface upon which may be placed ice trays i containing- Water for making iceculies f or other matter to be frozen. In order tothra mally shield such matter from air in the higher? located compartment 68; a protective hood]? is provided at the top wall of the housing 66:" The hood l3'jmay be formed of a, plurality of layers, "i f'of thin aluminum sheeting, for example, having insulating air gaps therebetween, The indi vidual layers 14 may be inverted U-shape in sec.-.. tion, the opposing vertical arms or legs being adapted to rest on the top surface of the housing S6 at reg-ions thereof closely adjacent to theside Walls of the inner shell 53. By employing aluminum sheeting having bright reflecting surfaces for the layers 74, heat transfer by radiation from. the compartment 68 to matter placed on the top. surface of the housing is effectively retardedby the hood 13 which acts to re-radiateheat backs. to the compartment 68. The hood or radiation protector 13 may also be formed of layers ofmaterial having poor thermal conducting properties, which are coated with aluminum foil. i I

While the housing 65 of the higher temperature coolingzelement Mb is shown in Fig. 3 as being substantiallymidway between the side Walls of the inner shell 53, it may be placed in any other position in the space 5|. The housing 65 may be formed with a ledge '15 at a side wall thereof which is directly opposite one or more indented regions 16 in a side wall of the inner liner 53 for supporting a perforated shelf H. Further, a shelf 18 may be provided substantially at the level of the bottom of the housing 65 which extends over the entire cross sectional area of the space 51. In such arrangement the housing 65 serves as a vertical partition between two compartments in the extreme upper part of the space 5|. It may also be desirable in certain instances to employ a shelf 18 which is imperforate and formed of insulating material to provide three subdivided compartments 61, 68 and 19.

In view of the foregoing, it will now be understood that the housin '56 constitutes the first horizontally extending partition disposed above the bottom horizontal insulated Wall defining the interior 5! of the cabinet 50. The horizontal partition formed by the housing 66 is spaced from the bottom horizontal insulated wall a distance less than half of the overall height of the cabinet interior 5| and defines the freezing section 61 in which the low temperature cooling element Ha is disposed closely adjacent to and in the immediate vicinity of such partition which serves as the roof or ceiling of the freezing compartment. The door 56 constitutes a single closure member at the front of the cabinet 58 for closing the front opening and gaining'access to all parts of the cabinet interior 5 I.

While a single embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, as pointed out in the following claims.

What is claimed is:

1. A refrigerator comprising a cabinet having the interior subdivided into compartments, absorption refrigeration apparatus having an inert gas circuit including an absorber and a low temperature cooling element and a higher temperature cooling element, said higher temperature cooling element being primarily effective to cool one compartment and said low temperature cooling element being primarily effective to cool another compartment which constitutes a freezing section, and structure including said low temperature cooling element which provides a top wall for'said freezing section and also serves as a supporting surface upon which matter to be frozen may be placed, said low temperature cooling ele-' ment being located at a level between the upper end of the absorber and the liquid level therein.

2. An absorption refrigeration system having an absorber and cooling structure comprising a low temperature cooling element and a higher a temperature cooling element, means to supply liquid refrigerant to the upper ends of said cooling elements for gravity flow therethrough, means connecting said absorber and cooling structure to form a circuit for circulation of gas solely by force developed within the system due to difference in weight of columns of gas rich and weak, respectively, in refrigerant vapor, a circuit for absorption liquid including said absorber and a generator, said cooling structure being so connected and arranged in said gas circuit that said low temperature cooling element in its entirety is disposed at a level between the upper part of said absorber and the liquid level in said absorption liquid circuit at the vicinity of said absorber. 3. An absorption refrigeration system as set forth in claim 2 including a connection for draining liquid by gravity from said low temperature cooling element to said absorption liquid circuit. 4. An absorption refrigeration system as set forth in claim 2 in which said means to supply liquid refrigerant to said cooling elements is so constructed and arranged that gas will always start circulating in one direction in said gas circuit when operation of the system is started.

5. A refrigerator comprising a cabinet having thermally insulated walls defining a space, absorption refrigeration apparatus having a gas circuit including a low temperature cooling element and a higher temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, means to supply liquid refrigerant to said cooling elements, said higher temperature cooling element being arranged to abstract heat from the upper part of said space, and a horizontal partition in the bottom art of said space, said partition and thermally insulated Walls defining a freezing compartment, said low temperature cooling element being vertically spaced from the bottom of said freezing compartment and disposed closely adjacent to and in the immediate vicinity of said partition which serves as the roof or ceiling of said freezing compartment.

6. A refrigerator as set forth in claim 5 in which said partition subdivides said space into said freezing compartment and a higher located compartment, and means for thermally shielding said partition from said higher located compartment.

7. A refrigerator comprising a cabinet having the interior thereof subdivided into compartments, absorption refrigeration apparatus having an inert gas circuit including a low temperature cooling element and a higher temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, said higher temperature cooling element being at a higher level than said low temperature cooling element, means to supply refrigerant to said cooling elements, said higher temperature cooling element being primarily effective to abstract heat from one compartment and said low temperature cooling element being primarily effective to abstract heat from another compartment which constitutes a lower temperature section, and structure the interior thereof subdivided into compartments, absorption refrigeration apparatus having an inert gas circuit including a low temperature" cooling element and a higher temperature cooling element and condensing means'for liquefying refrigerant vapor which is always in unobstructed communication with both of said cooling elements for delivering liquid refrigerant thereto, said higher temperature cooling element being primarily effective to cool one compartment and said low temperature cooling element being primarily effective to cool another compartment which constitutes a lower temperature section, ,said higher temperature cooling element. being above said low temperature cooling elem-ent,and structure includingsaid low temperature cooling element which provides a top wall for said lower temperature section and also serves as a'supportoperation of the refrigeration apparatus is 1 started.

9.: An; absorption refrigeration system having a circuit for inert gas including an absorberi'and. cooling structure comprising a low temperaturecooling element and a higher temperature cooling element, means to supply liquid refrigerant to said cooling elements, a circuit for absorption liquid including said absorber and a generator, said cooling structure being so connected and arranged in said gas circuit that said low temperature cooling element in its entirety is disposed at a level between the upper part of said absorber and the liquid level in said absorption liquid circuit at the vicinity of said absorber, and means for draining liquid from said higher temperature cooling element to said low temperature cooling element and for draining liquid from the latter to said absorption liquid circuit.

10. An absorption refrigeration system having a circuit for inert gas including an absorber and cooling structure comprising a low temperature cooling element and a higher temperature cooling element, means to supply liquid refrigerant to said cooling elements, the inert gas and liquid refrigerant flowing in the same direction in said higher temperature cooling element and in opposite directions in said low temperature cooling element, a circuit for absorption liquid including said absorber and a generator, said cooling structure being so connected and arranged in said gas circuit that said low temperature cooling element in its entirety is disposed at a level between the upper part of said absorber and the liquid level in said absorption liquid circuit at the vicinity of said absorber.

11. A refrigerator comprising a cabinet having thermally insulated walls defining a space, absorption refrigeration apparatus having a gas circuit including a low temperature cooling element and a higher temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, means to supply liquid refrigerant to said cooling elements, said higher temperature cooling element being arranged to abstract heat from the upper part of said space, and a horizontal partition in the bottom part of said space, said partition and thermally insulated walls defining a lower temperature compartment in which said partition serves as the roof or ceiling of such compartment and provides a supporting surface for matter to be frozen, such surface being in good heat conducting relation with said low temperature cooling element.

12. A refrigerator comprising a cabinet having thermally insulated walls defining a space, absorption refrigeration apparatus having a gas circuit 'mcluding a low temperature cooling element and a higher temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, means to supply liquid refrigerant to said cooling elements, said higher temperature cool- 'r'ing element :being arranged-to abstract heatfrom ithe upper-part of said space,v anda. horizontal V partition in' the bottom part of said space,. said partitionandxthermally insulatedwalls defining "a lower temperature compartment in which said ':=partition.servesas the roof or ceiling of such com 2' partment iandrprovides a supporting surface for 1 matter tor'beifrozen, such surface being in good i heat :conducting relation with said low :temperature:cooling:element,.and'means providing. ahori- ,rzontally; extending wall. above said supporting surface :forithermally shielding: matter on the latter from the region above such wall.

, 13. .A" refrigeratorcomprising a cabinet having theinterior thereof" subdivided into compartments, absorption refrigeration apparatus having an inert gas circuit including a low temperature cooling element and a higher temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, means to supply refrigerant to said cooling elements, said higher temperature cooling element being effective to abstract heat from one compartment and said low temperature cooling element being effective to abstract heat from another compartment which constitutes a freezing section, structure including said low temperature cooling element which constitutes the roof or uppermost horizontal wall of said freezing section and also serves as a supporting surface upon which ice trays and other matter to be frozen may be placed, and means at the underside of said upper horizontal wall of said freezing section for removably supporting one or more vessels therefrom.

14. A refrigerator comprising a cabinet having the interior thereof subdivided into compartments, absorption refrigeration apparatus having an inert gas circuit including a low temperature cooling element and a high temperature cooling element which are always in open communication with one another and operable at substantially the same pressure, means to supply refrigerant to said cooling elements, said higher temperature cooling element being effective to abstract heat from one compartment and said low temperature cooling element being effective to abstract heat from another compartment which constitutes a freezing section, structure including said low temperature cooling element which constitutes the roof or uppermost horizontal wallof said freezing section and also serves as a supporting surface upon which ice trays and other matter to be frozen may be placed, and means including a protective hood for matter placed on the top surface of the upper horizontal wall of said freezing section for thermally shielding such matter.

15. In a refrigerator comprising a cabinet having thermally insulated walls defining the interior thereof provided with a front opening and refrigeration apparatus associated therewith in-- all height of the. interior of the cabinet and defining the freezing section of the latter, said second cooling element comprising piping in the cabinet interior which is located above said first partition, structure forming a housing which is disposed in the cabinet interior and envelops the piping of said second cooling element, said housing including metal sheeting-having said piping in thermal contact therewith, and said first partition embodying said first cooling element and providing a good heat conductive path from the latter to the top surface of said first partition upon which can be placed matter to be frozen.

GUNNAR AXEL GRUBB. PER ARNE BACKTEMAN.

a 12 REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,171,712 Potter Sept. 5, 1939 2,297,275 Acheson Sept. 29, 1942 2,345,453 Brace Mar. 28,- 1944 2,345,505 Siedle Mar. 28, 1944 2,350,249 Osborn May 30, 1944 2,416,354 Shoemaker Feb. 25, 1947 2,462,240 Van Vliet et a1. Feb. 22, 1949 2,466,541 Gaugler Apr. 5, 1949 2,508,000

Sutton May 16, 1950 

